The
XmbTextEscapement, XwcTextEscapement and Xutf8TextEscapement functions
return the escapement in pixels of the specified string as a value, using
the fonts loaded for the specified font set. The escapement is the distance
in pixels in the primary draw direction from the drawing origin to the
origin of the next character to be drawn, assuming that the rendering of
the next character is not dependent on the supplied string.

Regardless of
the character rendering order, the escapement is always positive.

The function
Xutf8TextEscapement is an XFree86 extension introduced in XFree86 4.0.2.
Its presence is indicated by the macro X_HAVE_UTF8_STRING.